Respiratory masks are worn in environments where toxic or noxious contaminants are present in the air, for example paint spraying booths. The masks are worn to protect the wearer from inhaling the airborne contaminants. In some activities, flying particles, droplets, or other contaminants can be generated. These airborne materials may irritate a person's eyes, and therefore it is advisable that eye protection, as well as respiratory protection, be worn. A respiratory mask may be used, which covers the whole wearer's face or head, or when the mask itself does not provide eye protection, by using separate eye shields, goggles, or glasses.
When using eye protection, a respirator wearer's vision can be impaired if the viewing area of the eye protection becomes obscured, for example, as a result of being struck by flying particles or droplets. This particular risk may occur during certain activities, for example, paint spraying. For those activities, eye protection that is separate from the respiratory mask may be more attractive because it can be changed more easily if it becomes damaged.
Separate eye protectors, however, can also present problems for respirator wearers. One problem is that the eye protectors can mist up during use (because they may trap, or provide an escape route for, warm air from the mask or, in the case of goggles, simply because they seal tightly to the face) thereby also obscuring wearer vision. They also are not always easy to fit or remove when wearing a respiratory mask. Another problem can be a lack of compatibility between the eye protector and the respiratory mask. This situation particularly arises when the respirator wearer attempts to don goggles or glasses to protect his/her eyes. In order to fit the goggles/glasses correctly, the wearer may compromise the fit of the half-mask to the face by locating the goggles/glasses below the mask seal. Alternatively, the wearer may choose to compromise the fit of the goggles/glasses by locating the bridge of the goggles/glasses over the nose portion of the mask, which can lead to distorted vision, misting, and discomfort.
Many different eye/face protectors have been proposed, examples of which are described in U.S. Pat. Nos. 4,701,965, 4,945,574, 4,964,171, 4,965,887, and 5,666,671. U.S. Pat. No. 6,264,392 describes a pivot joint assembly that enables a face shield, used either on its own or in combination with a helmet, to be moved by the wearer through a number of pre-selected indexed positions between a fully-up position and a fully-down position. Protective helmets with pivotal visors are described in U.S. Pat. Nos. 4,109,320, 4,479,738, 5,185,889, and 5,987,651; German Patents 3630516 and 9401066; and Japanese Patent 7-216622.
There also have been proposals for combining eye protection with respiratory half masks, examples of which are described in U.S. Pat. Nos. 2,462,005, 2,740,400, 2,762,368, 3,971,368, 4,172,455, 5,630,412, and 5,682,879; International Applications WO 96/34658 and WO 97/04837; and European Patent 1,086,720. The disclosures of the documents are summarized briefly below:
U.S. Pat. No. 2,462,005 describes a face shield for a half mask that has a centrally-located inhalation filter cartridge and a centrally-located exhalation valve. The face shield is a flat piece of flexible transparent material, with an opening and associated straps formed in its lower edge to enable the face shield to be fitted onto the filter cartridge.
U.S. Pat. No. 2,740,400 describes a face shield for a half mask that has a central exhalation valve and two inhalation filters mounted on receptacles in the cheek regions of the mask. The face shield is pre-shaped to curve over the eye region of the wearer, and has two apertures positioned to fit over the filter receptacles before the filters are attached.
U.S. Pat. No. 2,762,368 describes an eye shield for use with a non-valved half mask. The eye shield is a flat piece of flexible, transparent material and is positioned on the mask by slots that engage with eyelets on the cheek regions of the mask. The head straps of the mask may pass through slots in the eye shield.
U.S. Pat. No. 3,971,368 describes a half mask worn with separate goggles that have their own headband. When in position, the goggles engage an actuating element on the mask and thereby open a valve that directs air from the mask into the goggles.
U.S. Pat. No. 4,172,455 describes an eye-piece that is pivotally mounted on a helmet to which a breathing mask is also connected by adjustable tension straps.
U.S. Pat. No. 5,630,412 describes an eye shield for use with a supplied air half mask, which can be removed while the mask remains in place. To that end, the eye shield has a fixing block that is inserted into a slideway on the mask.
U.S. Pat. No. 5,682,879 describes a 2-panel fold flat particulate mask with a permanently-attached eye shield.
International Application WO 96/34658 describes an eye shield having a body portion that clips over the cap of a centrally-located exhalation valve of a respiratory half mask. Although not described, the eye shield could apparently be removed from the mask while the latter is being worn.
International Application WO 97/04837 describes goggles for use with a face mask, the goggles being detachably-attached to the mask by a tongue-end-groove connection, and held sealingly against the wearer's face by a strap of the face mask.
European Patent 1,086,720 describes a respiratory mask on which a visor is pivotally-mounted so that the position of the visor in the line of sight of the wearer can be adjusted.
It is also known to provide face/eye shields for medical-type particulate masks. Examples of such combinations are described in U.S. Pat. Nos. 5,704,349, 5,446,925, 5,303,423, 5,020,533, and 4,944,294. In each case, the face/eye shield is permanently bonded to the respiratory mask.